The present invention relates to a temperature sensing probe for sensing rectal temperature of a patient. In particular, the present invention relates to a temperature sensing probe comprising a reusable handle and sensor array with a disposable balloon/sleeve assembly.
The prostate gland is a complex, chestnut-shaped organ which encircles the urethra immediately below the bladder and lies immediately adjacent the rectum. This relatively small organ, which is the most frequently diseased of all internal organs, is the site of a common affliction among older men, benign prostatic hyperplasia (BPH), as well as a more serious affliction, cancer. BPH is a non-malignant, bilateral nodular tumorous expansion of prostate tissue occurring mainly in the transition zone of the prostate. Left untreated, BPH causes obstruction of the urethra which usually results in increased urinary frequency, urgency, incontinence, nocturia and slow or interrupted urinary stream. BPH may also result in more severe complications, such as urinary tract infection, acute urinary retention, hydronephrosis and uraemia.
A fairly recent treatment method for BPH involves microwave thermal therapy, in which microwave energy is employed to elevate the temperature of tissue surrounding the prostatic urethra above about 45° C., thereby thermally damaging the tumorous BPH tissue. Delivery of microwave energy to tumorous prostatic tissue is generally accomplished by a microwave antenna-containing applicator, which is positioned within a body cavity adjacent the prostate gland. The microwave antenna, when energized, heats adjacent tissue due to molecular excitation and generates a radiation pattern which encompasses and necroses the tumorous prostatic tissue. The necrosed intraprostatic tissue is subsequently reabsorbed by the body, thereby relieving an individual from the symptoms of BPH.
One type of thermal therapy treatment of BPH is transurethral microwave thermotherapy. This method of treatment positions a Foley-type catheter containing a microwave antenna within the urethra adjacent to the prostate gland. The microwave antenna is energized to heat a selected volume of tumorous prostatic tissue surrounding the urethra to about 45° C. for a time sufficient to necrose the selected volume of tissue.
Due to the relatively close proximity of the rectum to the urethra, it is critically important in the course of transurethral microwave thermotherapy that the temperature of the rectum is maintained below a threshold temperature. Rectal temperatures greater than the threshold may cause damage to the rectum.
Typically, the temperature of rectal tissue adjacent the prostate is measured and monitored with a rectal temperature sensing probe. The probe supports one or more temperature sensing elements against a wall of the rectum adjacent to the prostate to provide the physician with essential information for controlling the location and degree of heat induced in the prostate. In providing a rectal probe to measure the temperature of rectal tissue adjacent the prostate, it is desirable to maintain the position of a temperature sensing device supported by the probe directly adjacent to the rectal wall to provide optimally accurate temperature readings. There is a continuing need for an improved rectal temperature sensing probe.